Inconsistent interpretation of HTTP requests in Puma - CVE-2020-11076

Vulnerability identifier: #VU28303

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-11076

CWE-ID: CWE-444

Exploitation vector: Remote access

Exploit availability: Public exploit is available

The vulnerability allows a remote attacker to perform HTTP request smuggling attack.

The vulnerability exists due to improper input validation in the Transfer-Encoding Header. A remote attacker can send a specially crafted HTTP request and perform HTTP request smuggling attack.

Puma
Opensuse
openEuler
Ubuntu
Fedora
puma (Ubuntu package)
rubygem-puma
rubygem-puma-debuginfo
rubygem-puma-debugsource
rubygem-puma-doc

Install updates from vendor's website.

Puma - addressed in versions 3.12.5, 4.3.4
puma (Ubuntu package) - update to Ubuntu Pro
rubygem-puma - update to 3.12.6-1
rubygem-puma-debuginfo - update to 3.12.6-1
rubygem-puma-debugsource - update to 3.12.6-1
rubygem-puma-doc - update to 3.12.6-1
rubygem-puma - update to 4.3.6-1.fc33

• Exploit #2990 - cougar (Puma, CVE-2020-11076 and CVE-2020-11077) (June 3, 2020)

• https://github.com/puma/puma/blob/master/History.md#434435-and-31253126--2020-05-22
• https://github.com/puma/puma/commit/f24d5521295a2152c286abb0a45a1e1e2bd275bd
• https://github.com/puma/puma/security/advisories/GHSA-x7jg-6pwg-fx5h

• HTTP Request Smuggling in Puma web server for Ruby
• OpenSUSE Linux update for rubygem-puma
• OpenSUSE Linux update for rubygem-puma
• Ubuntu update for puma
• openEuler 20.03 LTS SP1 update for rubygem-puma
• Fedora 33 update for rubygem-puma